Multi-well apparatus

ABSTRACT

A multi-well assembly according to one embodiment comprises a multi-well block and a guide plate. The multi-well block defines a plurality of wells, with each well having a fluid-impermeable bottom surface. The guide plate defines a plurality of fluid passageways corresponding to the wells of the multi-well block. The guide plate is configured such that, whenever the guide plate is registered with the multi-well block, fluid communication is established between each well and an associated fluid passageway.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.60/274,262, filed on Mar. 8, 2001.

FIELD

The present invention concerns multi-well apparatus, typically usefulfor chemical, biological and biochemical analysis.

BACKGROUND

In recent years, various areas of research have demanded cost-effectiveassays and reactions of diminishing scale, increasing efficiency andaccuracy, with high-throughput capacity. Multi-well devices withmultiple individual wells, such as multi-well plates or multi-wellblocks, are some of the most commonly used tools to carry out suchreactions and assays. A variety of multi-well arrangements, constructedaccording to standardized formats, are commercially available. Forexample, a multi-well device having ninety-six depressions or wellsarranged in a 12×8 array is a commonly used arrangement. Conventionalmulti-well devices may have wells with either fluid-impervious bottomsurfaces to retain matter in the wells or open bottoms, in which case areceptacle plate may be placed underneath the multi-well device tocollect matter flowing from the wells.

Test plates for numerous applications are well-known in the art. Forexample, test plates are known for use in culturing tissue samples.Other forms of test plates are adapted for carrying out chemicalreactions or for use in micro-chromatography.

For applications requiring filtration, respective filters may bepositioned in the wells of a multi-well device. In such applications,vacuum or pressure may be applied to facilitate filtration of fluidsamples in the wells of the device. Following filtration, the fluids maybe collected in individual containers or wells of a receptacle plate.

Despite these prior inventions, there exists a continuing need for newand improved multi-well apparatus and methods for their use.

SUMMARY

The present invention is directed toward aspects and features of amulti-well assembly for use in, for example, chemical, biological, andbiochemical analysis.

A multi-well assembly according to one representative embodimentcomprises a multi-well block and a guide plate. The multi-well block hasa plurality of wells, with each well having a fluid-impermeable bottomsurface. The guide plate defines a plurality of fluid passagewayscorresponding to the wells of the multi-well block. The guide plate isconfigured such that, whenever the guide plate is registered with themulti-well block, fluid communication is established between each welland an associated fluid passageway.

In an illustrated embodiment, the guide plate has a plurality ofprojections corresponding to the wells of multi-well block. Theprojections are configured to perforate the bottom surfaces ofrespective wells whenever the guide plate is registered with themulti-well block to allow the contents (e.g., chemicals) of each well toflow outwardly, such as under the force of gravity, through theperforated bottom surfaces of the wells and into respective fluidpassageways. The fluid passageways in a disclosed embodiment comprisechannels extending substantially longitudinally through the guide plateand each projection.

The multi-well assembly also may include a second multi-well block (alsotermed a “receptacle” block) for receiving or collecting the contents ofthe wells of the multi-well block. The receptacle block in particularembodiments has a plurality of wells, each of which corresponds to arespective fluid passageway of the guide plate. Thus, whenever thereceptacle block is registered with the guide plate and the multi-wellblock, a fluid path is defined between each well of the multi-wellblock, a respective fluid passageway of the guide plate, and arespective well of the receptacle block. An optional cover may beprovided for covering the open tops of the wells of the multi-wellblock.

According to another representative embodiment, a multi-well assemblycomprises a first plate and a second plate. The first plate has aplurality of wells. The second plate has a plurality of upwardlyextending fluid conduits, each of which is adapted to receive thecontents of a well whenever the first plate is registered with thesecond plate. In addition, the fluid conduits may be configured suchthat, whenever the first plate is registered with the second plate, eachfluid conduit extends upwardly into the lower portion of a respectivewell to receive fluid therefrom. In particular embodiments, the fluidconduits comprise projections formed with substantially longitudinallyextending passageways. The second plate also may be provided with anupwardly extending wall circumscribing each fluid conduit. The walls areconfigured such that, whenever the first plate is registered with thesecond plate, each wall matingly fits around the lower portion of arespective well to minimize cross-contamination between adjacent wells.

In another representative embodiment, a multi-well device includes aplurality of wells, with each well having a fluid-impervious lowersurface. A guide tray has a plurality of fluid passageways thatcorrespond to the wells of the multi-well device. The guide tray alsohas means for fluidly connecting each fluid passageway with acorresponding well whenever the guide tray is registered with themulti-well device.

According to yet another representative embodiment, a guide plate foruse with a multi-well device comprises a body having upper and lowermajor surfaces. A plurality of projections depend from the upper majorsurface and a plurality of outlet spouts depend from the lower majorsurface below the projections. Extending through each projection andoutlet spout is a fluid passageway or channel. In a disclosedembodiment, an upwardly extending wall surrounds each projection and isconfigured to matingly fit around the lower portion of a well of themulti-well device whenever the guide plate is registered with themulti-well device. In addition, each projection may be formed with acutting surface that is configured to perforate the bottom surface of awell whenever the guide plate is registered with the multi-well device.

According to another representative embodiment, a guide plate for usewith a multi-well device comprises a body having first and second majorsurfaces. A plurality of projections depend from one of the first andsecond major surfaces. Each projection is configured to perforate thebottom surface of a well of the multi-well device whenever the guideplate is registered with the multi-well device. In particularembodiments, the projections are shaped in the form of an ungula (i.e.,a cylindrical or conical section formed by intersecting a cylinder orcone with one or more planes oblique to its base) and may be formed witha longitudinally extending channel.

In another representative embodiment, a method of carrying out multiplechemical reactions comprises providing a multi-well device having aplurality of wells with fluid-impervious bottom surfaces and a guideplate defining a plurality of passageways corresponding to the wells.Reagents for the chemical reactions may be introduced into the wells ofthe multi-well device. Upon completion of the chemical reactions, theguide plate may be registered with the multi-well device so that thebottom of each well is in flow-through communication with a passagewayin the guide plate. Thus, the products of the chemical reactions arepermitted to flow through the passageways and, if a receptacle plate isprovided, into corresponding wells of the receptacle plate.

These and other features of the invention will be more fully appreciatedwhen the following detailed description of the invention is read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a multi-well assembly, according to oneembodiment, shown with a portion of the upper multi-well block brokenaway to show the upper surface of the guide plate, and with a portion ofthe guide plate broken away to show the wells of the lower multi-wellblock.

FIG. 2 is a side elevation view of the upper multi-well block of themulti-well assembly of FIG. 1, shown with a cover covering the open topsof the wells.

FIG. 3 is a perspective, sectional view of the upper multi-well block ofFIG. 1.

FIG. 4 is a bottom perspective view of the upper multi-well block ofFIG. 1.

FIG. 5 is a vertical section of the multi-well assembly of FIG. 1, shownwith a cover installed on the upper multi-well block and filterspositioned in each well.

FIG. 6 is a top perspective view of the guide plate of the multi-wellassembly of FIG. 1.

FIG. 7 is an enlarged perspective view of a portion of the guide plateshown partially in section.

FIG. 8 is an enlarged perspective view of a portion of the uppermulti-well block, shown partially in section, and a portion of the guideplate, shown partially in section, in which the wells of the uppermulti-well block are registered with corresponding fluid conduits of theguide plate.

FIG. 9 is a perspective view of the cover of FIG. 2.

DETAILED DESCRIPTION

Referring initially to FIG. 1, there is shown a multi-well assembly,indicated generally at 10, according one embodiment. Generally, theassembly 10 comprises a first multi-well block 12, a guide plate, ortray, 14 situated below the first multi-well block 12, and a secondmulti-well block 16 (also termed a “receptacle block”) situated belowthe guide plate 14. In use, chemical or biological matter is introducedinto the first multi-well block 12 for carrying out any of variouschemical, biological, and biochemical reactions and processes. Thesecond multi-well block 16 serves as a receptacle block for receivingchemical or biological matter from the first multi-well block 12, asdescribed in greater detail below.

Referring also to FIGS. 2-4, the first multi-well block 12 in theillustrated configuration has, as its name suggests, a generallyrectangular block-like shape and supports a 8×12 array of verticallydisposed, elongated wells, or cavities, 18. Such a 96-well array, withspecific (i.e., 9 mm) center-to-center spacing is a standardconfiguration for many commercially available multi-well test plates.The overall dimensional area of the first multi-well block 12, as wellas the guide plate 14 and the second multi-well block 16, provide for afootprint of the same size as a standard 96-well plate to permit usewith standard equipment holders, well washers, and the like.

Although in the illustrated embodiment the first multi-well block 12 isshown as having a generally block-like shape, the first multi-well block12 may be generally cylindrical in shape or have any of various othergeometric shapes. In addition, any number of wells 18 and anyarrangement of wells 18 may be used. For example, without limitation,other possible arrays of wells 18 include a 4×6 array and a 6×8 array.Although less desirable, in other embodiments, the first multi-wellblock 12 may support wells 18 that are not arranged in an ordered array.In still other embodiments, wells that are substantially shallower indepth than those of the illustrated embodiment may be used, in whichcase the first multi-well block 12 will have more of a plate-likeconfiguration, rather than the illustrated block-like shape. The wells18 may be configured to support volumes, for example, from about 100 μLto several mL per well, although wells having a larger or smallervolumetric capacity also may be used. In working embodiments, the wells18 are configured to hold about 2 mL to 3 mL per well.

The illustrated wells 18 have open tops 20 (FIGS. 1 and 3) andfluid-impermeable barriers 22 (FIGS. 3 and 4) that serve as bottomsurfaces for the wells 18. As best shown in FIGS. 3 and 5, each well 18has a generally rectangular (in the vertical direction) upper portion24, a cylindrical intermediate portion 26, and a cylindrical lowerportion 44. As shown, the upper portion 24 and lower portion 44 of eachwell 18 may be slightly tapered so that their cross-sectional profileexhibits decreasing width from top to bottom. The lower end of eachlower portion 44 is covered or sealed by the respective fluid barrier 22(FIGS. 2 and 4). In addition, as shown in FIGS. 3 and 5, the upperportion 24 of each well 18 may be formed with a curved bottom surface 28to prevent the contents of the well 18 from settling in the upperportion 24. In alternative embodiments, the well 18 may have any ofvarious other configurations. For example, an upper portion 24 may havea circular transverse cross-section or square-shaped transversecross-section with rounded corners. Alternatively, the wells 18 may beprovided with a constant cross-sectional shape along their entirelengths.

In addition, in still other embodiments, the barriers 22 may bedisplaced upward from the bottom edges of the lower portions 44. Forexample, the barriers 22 may be positioned within the intermediateportions 26 or the lower portions 44 of the wells 18. In any event, thebarriers 22 serve to retain matter (e.g., chemicals) introduced into therespective wells 18.

The barriers 22 desirably are about 0.005 to 0.015 inch thick, with0.010 inch being a specific example, although thinner or thickerbarriers 22 can be used. In other embodiments, the barriers 22 may havea variable thickness. For example, a barrier 22 may have a convex shapeso that its thickness is greatest at its center, or alternatively, aconcave shape so that its thickness is greatest at its periphery.

Referring to FIGS. 2, 5, and 9, an optional cover or lid 60 may beprovided for covering the open tops 20 of the wells 18. The cover 60 inthe configuration shown comprises a fluid-impermeable top portion 62 andlegs 64 that extend downwardly from opposing sides of the top portion62. The bottom of each leg 64 forms an inwardly extending latch 66 thatis dimensioned to fit within a corresponding notch 58 defined in a sideof the first multi-well block 12 (FIGS. 2 and 5). The legs 62 desirablyare made from a semi-flexible material to permit slight bending orflexing of the legs 62 when installing or removing the cover 60. Asealing member, such as a flat gasket (not shown), may be positionedbetween the open tops 20 and the cover 60 to ensure a fluid-tight seal.To remove the cover 62, the bottom ends of legs 64 are pulled away fromthe sides of the multi-well block 12 until the latch portions 66 areremoved from their associated notches 58, at which point the cover 62can be lifted away from the multi-well block 12.

Referring again to FIG. 1, the second multi-well block 16, like thefirst multi-well block 12, has an ordered array of wells 48, eachcorresponding to a respective well 18 of the first multi-well block 12.The guide plate 14 is configured to direct the flow of matter from thewells 18 of the first multi-well block 12 to corresponding wells 48 ofthe second multi-well block 16, as described below. In the illustratedembodiment, the second multi-well block 16 has the same construction asthe first multi-well block 12, however, this is not a requirement. Forexample, if the first multi-well block 12 and the guide plate 14 conformto a standardized format, such as the illustrated 96-well format, anysuitable commercially available receptacle block may be used in lieu ofthe illustrated second multi-well block 16.

Referring to FIGS. 5-8, the guide plate 14, in the illustratedconfiguration, comprises a body 38 having an upper major surface 40 anda lower major surface 42. The guide plate 14 has an ordered array ofupwardly extending fluid conduits in the form of projections 32, each ofwhich corresponds to a respective well 18 of the first multi-well block12. The guide plate 14 also may have an ordered array of downwardlyextending outlet spouts 50 located below respective projections 32. Theguide plate 14 is formed with respective bores, or channels, 34extending through each projection 32 and outlet spout 50.

The projections 32 are configured to perforate the respective barriers22 to allow the contents of each well 18 to flow outwardly therefromwhenever guide plate 14 is registered with the first multi-well block 12(as shown in FIGS. 5 and 8). As used herein, to “register” the guideplate 14 with the first multi-well block 12 means to align eachprojection 32 with the respective barrier 22 of a corresponding well 18and to press together the guide plate 14 and the first multi-well block12 until the projections 32 extend into the respective lower portions 44of the wells 18. Likewise, the second multi-well block 16 can beregistered with the guide plate 14 by aligning the open tops of thewells 48 with corresponding outlet spouts 50 of the guide plate 14 andpressing the guide plate 14 and the second multi-well block 16 togetherso that the outlet spouts 50 extend into the respective wells 48 (FIG.5).

As best shown in FIG. 7, the shape of each projection 32 in theillustrated embodiment is that of a cylindrical section formed byintersecting a cylinder with two planes oblique to the base of thecylinder in the manner shown. Thus, two flat, upwardly angled surfaces54 a, 54 b are provided that converge at the top, or crest, of theprojection 32 to form a cutting edge 56. The cutting edge 56 ispositioned to cut through a respective barrier 22 whenever the guideplate 14 and the first multi-well block 12 are pressed together. Otherforms for the projections 32 alternatively may be used. For example, theprojections 32 may be shaped in the form of a cone, a cylinder, or anyvariation thereof, and may or may not be provided with a cutting edge,such as shown in FIG. 7, to facilitate perforation of the barriers 22.

In alternative embodiments, the barriers 22 may be coupled to the lowerportions 44 of the wells 18 in a manner that allows the barriers to beremoved from sealing the bottom of their respective wells 18 withoutbeing perforated or otherwise damaged whenever the guide plate 14 isregistered with the first multi-well block 12. For example, a barrier 22may be hingedly connected to a lower portion 44 such that the barrier 22remains in a normally closed position for retaining the contents of thewell 18 whenever the first multi-well block 12 is not registered withthe guide plate 14. The hinged barrier 22 is caused to move to an openposition by a respective projection 32 to permit the contents of thewell 18 to escape therefrom whenever the first multi-well block 12 isregistered with the guide plate 14. The barrier 22 in this configurationmay be biased toward its normally closed position so that itautomatically closes or seals the lower portion 44 whenever the guideplate 14 is detached from the first multi-well block 12.

In another embodiment, a barrier 22 may be configured such that it isnormally biased in a closed position and is caused to move upwardlythrough a lower portion 44 by a respective projection 32 whenever thefirst multi-well block 12 is registered with the guide plate 14. In thisconfiguration, the lower portion 44 is tapered from top to bottom sothat an opening is created between the periphery of the barrier 22 andthe inner surface of the lower portion 44 as the barrier is moved in anupward direction by the respective projection 32.

In the embodiment shown in FIGS. 5-8, each projection 32 iscircumscribed by an upper wall 36 depending from the upper major surface40 of the guide plate 14. Each outlet spout 50 is similarlycircumscribed by a lower wall 52 depending form the lower major surface42. As shown in FIGS. 5 and 8, whenever the guide plate 14 is registeredwith the first multi-well block 12, each upper wall 36 of the guideplate 14 matingly fits around the lower portion 44 of a correspondingwell 18. This provides for a substantially fluid-tight passagewayextending between each well 18 and corresponding channel 34 tosubstantially reduce cross-contamination between adjacent wells 18. Inaddition, each lower wall 52 is dimensioned to fit within an open top 46of a corresponding well 48 of the second multi-well block 16. Thus,whenever the first multi-well block 12, the guide plate 14, and thesecond multi-well block 16 are assembled in the manner shown in FIG. 5,the contents of each well 18 of the multi-well block 12 are allowed toflow through the channels 34 of the guide plate 14 into correspondingwells 48 of the receptacle block 16.

Guide-plate and projection configurations other than the illustratedconfigurations also may be used. For example, in alternativeembodiments, one or more channels may be formed in the guide plate 14 inthe space between each projection 32 and its respective upper wall 36,rather than through the projections 32 themselves, to permit thecontents of the wells 18 to flow through the guide plate 14 whenever theguide plate 14 is registered with the first multi-well block 12. Instill other embodiments, the upper walls 36 are dimensioned to beinserted into respective lower portions 44 of the wells 18.

As shown in FIG. 5, optional filters 30 may be positioned within thewells 18 of the first multi-well block 12 to filter chemicals or othermatter introduced into the wells 18. Alternatively, filters (not shown)can be positioned in the channels 34 of the guide plate 14 and/or in thewells 48 of the second multi-well block 16. The filters 30 may compriseany suitable material, such as, for example, polypropylene,polyethylene, glass fiber, and the like.

The first multi-well block 12, the guide plate 14, the second multi-wellblock 16, and the cover 60 desirably are formed of a substantiallyrigid, water-insoluble, fluid-impervious material that is chemicallynon-reactive with the matter to be introduced into the multi-wellassembly 10. The term “substantially rigid” as used herein is intendedto mean that the material will resist deformation or warping under lightmechanical or thermal load. Suitable materials include, withoutlimitation, polystyrene, polyethylene, polypropylene, polyvinylidinechloride, polytetrafluoroethylene (PTFE), polyvinyledenefluoride (PVDF),glass-impregnated plastics, and stainless steel, among others. Inworking embodiments, polypropylene is used because it is easily amenableto varying temperature and pressure conditions, and is easy tofabricate.

The first multi-well block 12, the guide plate 14, the second multi-wellblock 16, and the cover 60 may be formed by any suitable method. Forexample, using conventional injection-molding techniques, each componentof the assembly 10 (i.e., the first multi-well block 12, the guide plate14, the second multi-well block 16, and the cover 60) can be formed as aunitary structure. In an alternative approach, various parts of eachcomponent may be formed and bonded together using conventionalthermal-bonding techniques. For example, the wells 18 and/or thebarriers 22 can be separately formed and subsequently thermally bondedtogether to form the first multi-well block 12.

The multi-well assembly 10 may be used in any of various chemical,biological, and biochemical reactions and processes such as, withoutlimitation, solution-phase or solid-phase chemical synthesis andreactions, protein-derivitization assays, protein-caption assays,biotinylation and fluorescence labeling assays, magnetic separationassays, chromatography, and culturing of microorganisms, among others.The processes in the assembly 10 may be carried out at room temperature,below room temperature, or above room temperature. In addition, theassembly 10 supports multiple simultaneous reactions.

In using the multi-well assembly 10 for, for example, carrying outmultiple chemical reactions, reagents are introduced into the wells 18of the first multi-well block 12, using, for example, a multi-channelpipette. In this manner, the first multi-well block 12 serves as a“reaction block” for carrying out the multiple chemical reactions. Aspreviously mentioned, the barriers 22 serve to retain the reagents inthe wells 18 during the reaction step. If desired, the cover 60 may beplaced on the first multi-well block 12 to prevent the escape of gasesthrough the open tops 20 of the wells 18 as the reactions occur, and/orto prevent contamination or cross-contamination of the reactions.

Upon completion of the reaction step, the bottom of each well 18 ismated and coaxially aligned with a respective upper wall 36 of the guideplate 14, and each well 48 of the second multi-well (receptacle) block16 is mated and aligned with a respective lower wall 52 of the guideplate 14. The first multi-well block 12, the guide plate 14, and thereceptacle block 16 may then be placed in a conventional pressingapparatus (not shown). The pressing apparatus is operated to press theassembly together to cause the projections 32 to perforate therespective barriers 22, thereby allowing the reaction products in eachwell 18 to flow through the channels 34 of the guide plate 14 and intothe respective wells 48 of the receptacle block 16 for analysis and/orstorage.

In specific working embodiments, the assembly 10 is configured such thatabout 5 lb to 15 lb of force per well 18 during pressing is sufficientto cause the projections 32 to perforate the barriers 22, although thisis not a requirement. In other embodiments, the assembly 10 may beconfigured to allow a user to register the first multi-well block 12,the guide plate 14, and the receptacle block 16 without the use of apressing apparatus.

After pressing, conventional techniques may be used to facilitateremoval of the contents of the wells 18. For example, the assembly 10may be centrifuged, or a pressure differential may be created across theassembly 10, as well known in the art. A pressure differential may becreated by, for example, applying positive pressure from acompressed-gas source (e.g., compressed air) to the wells 18 of thefirst multi-well block 12 or, alternatively, applying a vacuum to thewells 48 of the receptacle block 16.

After the reaction products are removed from the receptacle block 16,the assembly 10 may be cleaned and re-used in another process. Ifdesired, the bottom of the wells 18 may be re-sealed by, for example,welding a mat of suitable material (e.g., polypropylene) to the bottomof the wells 18. Otherwise, the first multi-well block 12 may be used asis, that is, without any barriers 22 in place to retain matterintroduced into the wells 18.

In addition, in other methods of use, after executing a first reactionstep, the receptacle block 16 may be used to perform a subsequentreaction or processing step, and additional chemicals or reagents may beintroduced into the wells 48. Thereafter, the receptacle block 16 can beregistered with another guide plate 14 and receptacle block 16 in themanner described above. In this manner, the receptacle block 16 is usedas a reaction block in the subsequent reaction or processing step.

The invention has been described with respect to particular embodimentsand modes of action for illustrative purposes only. The presentinvention may be subject to many modifications and changes withoutdeparting from the spirit or essential characteristics thereof. Wetherefore claim as our invention all such modifications as come withinthe scope of the following claims.

1. A multi-well assembly, comprising: a multi-well block having aplurality of wells, each well having an open top and a fluid-impermeablebottom surface; and a guide plate defining a plurality of fluidpassageways, each fluid passageway corresponding to a respective well ofthe multi-well block, the guide plate being configured such thatregistering the guide plate with the bottom of the multi-well blockestablishes fluid communication between each well and an associatedfluid passageway to allow fluid to flow from each well into anassociated fluid passageway, wherein the guide plate has upwardlyextending integral projections that are non-removable from the guideplate, wherein the projections extend through and open the bottomsurfaces of the wells whenever the guide plate is registered with themulti-well block; wherein the bottom surfaces of the wells areimpermeable to a fluid with which the multi-well block is used wheneverthe guide plate is not registered with the multi-well block.
 2. Theassembly of claim 1, wherein each projection is configured to perforatethe bottom surface of a well.
 3. The assembly of claim 1, furthercomprising a filter disposed in each well.
 4. The assembly of claim 1,further comprising a receptacle block having a plurality of wells eachcorresponding to a respective fluid passageway of the guide plate suchthat, whenever the receptacle block is registered with the guide plateand the guide plate is registered with the multi-well block, fluidcommunication is established between each well of the multi-well block,a respective fluid passageway of the guide plate, and a respective wellof the receptacle block.
 5. The assembly of claim 1, further comprisinga cover for covering the open tops of the wells of the multi-well block.6. The assembly of claim 1, wherein each projection is formed generallyin the shape of an ungula having two non-parallel, upwardly facingangled surfaces intersecting at a cutting edge for perforating thebottom surface of a respective well.
 7. The assembly of claim 4, whereinthe receptacle block has a substantially similar construction to that ofthe multi-well block.
 8. A multi-well assembly, comprising: a multi-wellblock having a plurality of wells, each well having an open top and afluid-impermeable bottom surface; and a guide plate defining a pluralityof fluid passageways, each fluid passageway corresponding to arespective well of the multi-well block, the guide plate beingconfigured such that, whenever the guide plate is registered with thebottom of the multi-well block, fluid communication is establishedbetween each well and an associated fluid passageway to allow fluid toflow from each well into an associated fluid passageway, wherein theguide plate has upwardly extending projections that extend through andopen the bottom surfaces of the wells whenever the guide plate isregistered with the multi-well block; wherein the guide plate comprises:a body having generally flat first and second opposed major surfaces,the projections depending from the first major surface; and a pluralityof outlet spouts depending from the second major surface; wherein eachof said fluid passageways extends through a respective projection and arespective outlet spout.
 9. The assembly of claim 8, wherein the guideplate further comprises a plurality of first walls depending from thefirst major surface and a plurality of second walls depending from thesecond major surface, each first wall being concentrically disposedabout a respective projection and each second wall being concentricallydisposed about a respective outlet spout.
 10. The assembly of claim 9,wherein each first wall is configured to matingly fit and form afluid-tight seal around a bottom portion of a corresponding well of themulti-well block, thereby minimizing cross-contamination between fluidsflowing from different wells.
 11. The assembly of claim 8, furthercomprising a receptacle block having a plurality of wells eachcorresponding to a respective outlet spout of the guide plate such that,whenever the receptacle block is registered with the guide plate and theguide plate is registered with the multi-well block, each outlet spoutextends into a respective well of the receptacle block so as toestablish fluid communication between each well of the multi-well block,a respective fluid passageway of the guide plate, and a respective wellof the receptacle block.
 12. A multi-well assembly comprising: a firstplate having a plurality of wells, each well having a bottom end and anopen top end opposite the bottom end for introducing fluid into thewells; and a second plate having first and second opposed majorsurfaces, the first surface having a plurality of upwardly extendingfluid conduits, the second surface having a plurality of downwardlyextending outlet spouts, each outlet spout being in fluid communicationwith a respective fluid conduit; wherein, whenever the first plate isregistered with the second plate, each fluid conduit extends upwardlythrough the bottom end of a respective well to receive fluid therefrom.13. The assembly of claim 12, wherein: the second plate comprises aunitary structure and the first and second surfaces of the second plateare generally flat; each well has a fluid-tight bottom surface; andwhenever the first plate is registered with the second plate, each fluidconduit perforates a bottom surface of a respective well so that thefluid conduit is in fluid communication with the well.
 14. The assemblyof claim 12, further comprising a receptacle block having a plurality ofcontainers, each outlet spout being configured to extend into arespective container of the receptacle block.
 15. The assembly claim 12,wherein, whenever the first plate is registered with the second plate,each well and a corresponding fluid conduit define a substantiallyfluid-tight passageway.
 16. The assembly of claim 12, wherein each fluidconduit comprises a respective projection formed with a longitudinallyextending channel.
 17. The assembly of claim 12, wherein the secondplate comprises an upwardly extending wall circumscribing each fluidconduit, each wall having an inner surface and each fluid conduit havingan outer surface, the inner surface of each wall being configured tomatingly fit around a lower portion of a respective well whenever thefirst plate is registered with the second plate, the entire innersurface of each wall being spaced radially outwardly from the outersurface of a respective fluid conduit so as to define a spacetherebetween for receiving the lower portion of a respective well.
 18. Amulti-well testing apparatus, comprising: a multi-well device comprisinga plurality of wells each having a liquid-impervious lower surface andan opening spaced from the lower surface for introducing liquid into thewells; and a guide tray comprising a plurality of fluid passageways,each fluid passageway corresponding to a well of the multi-well device,the guide tray comprising means for fluidly connecting each fluidpassageway with a corresponding well upon the guide tray is beingpositioned underneath and registered with the multi-well device, theguide tray comprising a one-piece construction; wherein the lowersurfaces of the wells are impervious to a fluid with which themulti-well device is used whenever the guide tray is not registered withthe multi-well device; wherein said means for fluidly connecting eachfluid passageway with a corresponding well comprises a plurality ofupwardly extending projections configured to perforate the lowersurfaces of the respective wells whenever the guide tray is registeredwith the multi-well device.
 19. The apparatus of claim 18, furthercomprising a respective filter disposed in each well.
 20. The apparatusof claim 18, wherein the fluid passageways extend through respectiveprojections and the guide tray further comprises an upwardly extendingwall circumscribing each projection, each wall being configured topress-fit and form a fluid-tight seal around a lower portion of arespective well whenever the guide tray is registered with themulti-well device, the walls preventing cross-contamination betweenfluids flowing from different wells.
 21. The apparatus of claim 18,further comprising a receptacle block comprising a plurality of wellseach corresponding to a respective fluid passageway of the guide traysuch that, whenever the receptacle block is registered with the guidetray and the guide tray is registered with the multi-well device, fluidcommunication is established between each well of the multi-well device,a respective fluid passageway of the guide tray, and a respective wellof the receptacle block.
 22. A guide plate for use with a multi-welldevice, the guide plate comprising: a body having upper and lower majorsurfaces; a plurality of projections depending from the upper majorsurface; a plurality of outlet spouts depending from the lower majorsurface, each outlet spout being positioned below a respectiveprojection; a respective fluid passageway extending through eachprojection and outlet spout; and a respective upwardly extending wallconcentrically disposed about each projection; wherein the guide platecomprises a unitary structure.
 23. The guide plate of claim 22, wherein:the upper major surface is generally flat and continuous between thewalls; and the lower major surface is generally flat and continuousbetween the outlet spouts.
 24. The guide plate of claim 22, furthercomprising a respective downwardly extending wall concentricallydisposed about each outlet spout wherein each outlet spout extends fromthe lower major surface a greater distance than its respectivedownwardly extending wall.
 25. The guide plate of claim 22, wherein eachprojection defines a respective cutting surface.
 26. A guide plate foruse with a multi-well device having a plurality of wells, the guideplate comprising: a body having first and second major surfaces that aregenerally flat and parallel to each other; a plurality of projectionsdepending from the first major surface, each projection being configuredto perforate the bottom surface of a respective well of the multi-welldevice; and a plurality of walls, each surrounding a respectiveprojection and being configured to matingly fit around a bottom portionof a corresponding well of the multi-well device; wherein eachprojection defines a passageway to receive the contents of acorresponding well of the multi-well device.
 27. The guide plate ofclaim 26, further comprising a plurality of outlet spouts depending fromthe second major surface, wherein each passageway extends through arespective projection and a respective outlet spout.
 28. The guide plateof claim 26, further comprising: a plurality of outlet spouts extendingfrom the second major surface opposite the projections; and a pluralityof walls extending from the second major surface and disposed about theoutlet spouts, wherein each outlet spout extends from the second majorsurface a distance greater than its respective wall.
 29. A guide platefor use with a multi-well device having a plurality of wells, the guideplate comprising: a body having first and second major surfaces; and aplurality of projections depending from one of the first and secondmajor surfaces, each projection being configured to perforate the bottomsurface of a respective well of the multi-well device; wherein eachprojection is formed generally in the shape of an ungula comprising agenerally cylindrical portion having two non-parallel, substantiallyflat upwardly facing angled surfaces intersecting at a cutting edge forperforating the bottom surface of a respective well.
 30. A multi-wellassembly comprising: a multi-well block having a plurality of wells,each well having a fluid-impermeable bottom surface; a guide platedefining a plurality of fluid passageways, each fluid passagewaycorresponding to a respective well of the multi-well block, the guideplate being configured such that, registering the guide plate with thebottom of the multi-well block; establishes fluid communication betweeneach well and an associated fluid passageway to allow fluid to flow fromeach well into an associated fluid passageway; wherein the bottomsurfaces of the wells are impermeable to a fluid with which themulti-well block is used when the guide plate is not registered with themulti-well block; and a receptacle block having a plurality of wellseach corresponding to a respective fluid passageway of the guide platesuch that, whenever the receptacle block is registered with the guideplate and the guide plate is registered with the multi-well block, fluidcommunication is established between each well of the multi-well block,a respective fluid passageway of the guide plate, and a respective wellof the receptacle block; wherein the receptacle block has the sameconstruction as the construction of the multi-well block.